Melanotan II vs IGF-1 LR3

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

Melanotan II

Melanotan II is a synthetic peptide analog of α-MSH with broader receptor activity than Melanotan I. It produces tanning effects and has notable effects on sexual function and appetite suppression.

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IGF-1 LR3

IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a modified version of IGF-1 with extended half-life and enhanced potency. The modifications prevent binding to IGF binding proteins, increasing bioavailability.

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Side-by-Side Comparison

AspectMelanotan IIIGF-1 LR3
MechanismNon-selective melanocortin receptor agonist affecting MC1R (tanning), MC3R and MC4R (sexual function and appetite). This broader activity explains its multiple effects beyond tanning.Binds to IGF-1 receptors to promote protein synthesis, muscle growth, and fat metabolism. The LR3 modification (13 amino acid extension and arginine substitution) extends half-life from minutes to 20-30 hours.
Typical DosageTypical protocols: 0.25-0.5mg daily during loading phase for 1-2 weeks, then 0.5-1mg before UV exposure for maintenance. Start low to assess tolerance.Research protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles.
AdministrationSubcutaneous injection. Usually combined with UV exposure for tanning effects. Nasal spray formulations exist but have lower bioavailability.Intramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off.
Side EffectsNausea (common initially), facial flushing, spontaneous erections, increased libido, appetite suppression, and mole darkening.Hypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions.
Best For

What They Have in Common

Both Melanotan II and IGF-1 LR3 are commonly used for:

Key Differences

Unique to Melanotan II:

Unique to IGF-1 LR3:

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